Non-Scratch Abrasive Composite

ABSTRACT

The present invention is an abrasive composite including a first crosslinkable binder component, wherein when polymerized, has a glass transition temperature (Tg) below room temperature and a modulus of less than about 150 MPa: a second crosslinkable binder component having a Tg above room temperature; a material capable of initiating addition polymerization; and particulate grains having a Mohs hardness value of less than or equal to about 3.

BACKGROUND

Consumer interest in non-scratch scouring/cleaning products for use inhome cleaning is increasing due to the desire to protect high-valuesurfaces that are prone to damage from hard minerals and resins. Inaddition, it is also desirable if the cleaning product does not becomesoiled itself during the cleaning process. That is, it is desirable ifthe cleaning product either resists resist soil buildup on its surfacesor can be rinsed clean of soils after use.

An informal theory of abrasive performance posits that workpiecematerial removal rate is related to the abrasive material's mechanicalproperties (i.e., hardness), size, and shape (i.e., sharpness). On theother hand, the likelihood of an abrasive material producing scratcheson a workpiece is generally discussed in terms of the relative hardnessof the abrasive material and the workpiece. Though size and shapecertainly affect whether an abrasive will scratch and how noticeable thescratches are, actually forming a scratch requires the deformation ofthe workpiece by the abrasive material. For this to occur, the abrasivematerial must be stiffer than the workpiece. Thus, provided that theabrasive material is not so hard as to deform the workpiece, soilslocated on the surface of the workpiece having a lower hardness than theworkpiece itself can be effectively cleaned by an abrasive materialboasting sizes and shapes amenable to high soil removal rates, namelyrelatively tall protrusions with relatively sharp edges, for example,square pyramid-shaped abrasive protrusions having heights of about 500microns and base widths between 500-1200 microns, wherein formed edgeshave radii of curvature generally less than 50 microns.

BRIEF DESCRIPTION OF THE DRAWINGS

This disclosure may be more completely understood in consideration ofthe following detailed description of various embodiments of thedisclosure in connection with the accompanying drawings, in which:

FIG. 1 shows a perspective view of a first embodiment of a cleaningarticle of the present invention.

FIG. 2 shows a perspective view of a second embodiment of a cleaningarticle of the present invention.

FIG. 3 shows a perspective view of a third embodiment of a cleaningarticle of the present invention.

While the above-identified figures set forth several embodiments of thedisclosure, other embodiments are also contemplated, as noted in thedescription. In all cases, this disclosure presents the invention by wayof representation and not limitation. It should be understood thatnumerous other modifications and embodiments can be devised by thoseskilled in the art, which fall within the scope and spirit of theprinciples of the invention.

SUMMARY

In one embodiment, the present invention is an abrasive compositeincluding a first crosslinkable binder component wherein whenpolymerized, has a glass transition temperature (T_(g)) below roomtemperature and a modulus of less than about 150 MPa; a secondcrosslinkable binder component having a T_(g) above room temperature; acomponent capable of initiating addition polymerization; and particulategrains having a Mohs hardness value of less than or equal to about 3.

In another embodiment, the present invention is a structured abrasivearticle including a substrate and an abrasive composite adhered to thesubstrate. The abrasive composite includes a first crosslinkable bindercomponent wherein when polymerized, has a glass transition temperature(T_(g)) below room temperature and a modulus of less than about 150 MPa;a second crosslinkable binder component having a T_(g) above roomtemperature; a component capable of initiating addition polymerization;and particulate grains having a Mohs hardness value of less than orequal to about 3.

DETAILED DESCRIPTION

The present invention is an abrasive composite that can be used forcleaning or scouring that is substantially non-scratch and is able to besubstantially rinsed clean of soils that accumulate on the surface ofthe abrasive composite during use. The abrasive composite is designed tohave high scouring performance without appreciable damage to theunderlying substrate being cleaned. In one embodiment, the abrasivecomposite can be used for home cleaning that entails substantially no orminimal damage to materials such as, for example,poly(tetrafluoroethylene), stainless steel, and hard plastics. Afterbeing used to clean, the abrasive composite can be essentially rinsedclean of debris removed from the surfaces being cleaned. In addition,the abrasive composite of the present invention is durable and wearswell.

The abrasive composite of the present invention is formed fromdispersing a mineral or particulate grain phase in an organic binderphase. In the abrasive composite, relatively particulate grains arebound together by a binder that serves as a dispersing medium for theparticulate grains and provides the means of attachment of the abrasivecomposites to a substrate or backing if desired. These particulategrains primarily act as a filler and viscosity modifier in the uncuredliquid precursor, in contrast to traditional coated or nonwovenabrasives, whose particulate grains generally have high values of Mohshardness and are capable of removing significant material from aworkpiece by gouging in a manner dependent on the particle grain'sshape, hardness, and size and the pressure and geometry of the abradingoperation. In this application, such gouges are framed as “scratches”,and while individual particulate grains with a low value of Mohshardness may not produce a visible scratch in a test surface, theminerals can affect the scratching by modifying the mechanicalproperties of the composite in accordance with general mixing rules forcomposites. In one embodiment, the abrasive composites of the presentinvention contain particulate grains having a Mohs hardness of less thanor equal to about 3. In one embodiment, the particulate grain phaseincludes an inorganic mineral having a d₉₀ of less than about 50 micron,and particularly less than about 30 micron, and a Mohs hardness value ofless than or equal to about 3. Increases in the particle sizedistribution increases the probability of scratching and decreasescontrol over the rheological properties of the liquid slurry prior tocuring.

Examples of particulate grains having a Mohs hardness of less than 3include, but are not limited to: clays (such as kaolinite,montmorillonite, illite, chlorite clays, talc, soapstone), gypsum,calcium carbonate (such as limestone and marble), mica, halite, and jet.Additionally, numerous soft organic materials can provide the samefunctions as soft particulate mineral grains, such as crushed or groundshells of nuts/fruits including, but not limited to: almond, argan,coconut, hazelnut, macadamia, pecan, pine, pistachio, and walnut;crushed or ground pits/kernels of fruits including. but not limited to:apricot, olive, peach, cherry, plum, palm, and tagua; crushed or groundcorn cob; crushed or ground shells of arthropods; wood flour; crushed orground synthetic polymeric materials including but not limited to anythermoplastic polymer or any thermoset polymer; and crushed, ground, orunmodified naturally-derived polymeric materials including, but notlimited to: polyhydroxyalkanoates; precision-shaped synthetic polymericmaterials. In one embodiment, the abrasive composite includes more thanone type of particulate grain.

In one embodiment, the abrasive composite includes between about 26% andabout 80%, particularly between about 47% and about 65%, and moreparticularly between about 52% and about 61% by weight particulategrains.

The binder of the abrasive composite must be capable of providing amedium in which the particulate grains can be distributed. The bindergenerally includes a soft crosslinkable binder component, a hardcrosslinkable binder component, and a material that is capable ofinitiating addition polymerization. The soft crosslinkable bindercomponent, when polymerized, has a glass transition temperature (T_(g))below room temperature (thereby being rubbery and capable ofdeformation) and a modulus of less than about 150 MPa. In oneembodiment, the soft crosslinkable binder component includes a urethanediacrylate or triacrylate. An example of a suitable soft crosslinkablebinder component includes, but is not limited to, an aliphatic urethanediacrylate. In one embodiment, the soft crosslinkable binder component,when polymerized, has an elongation % at break of greater than about25%.

The hard crosslinkable binder component has a T_(g) above roomtemperature (thereby being glassy and stiff). In one embodiment, thehard crosslinkable binder component includes a difunctional ortrifunctional acrylate. An example of a suitable hard crosslinkablebinder components includes, but is not limited to, trimethylolpropanetriacrylate.

In one embodiment, the material capable of initiating additionpolymerization is a UV photoinitiator.

Empirically, no single binder material subject to screening produced thedesired combination of high cleaning performance and low surfacescratching. Cleaning performance is benefitted by higher modulus, to thedetriment of surface damage avoidance, while lower modulus benefits theavoidance of surface damage, to the detriment of cleaning performance.By using a miscible blend of soft and hard binder components, the glasstransition and stiffness of the binder mixture can be tuned to optimizethe balance of cleaning performance and surface damage, avoiding themore costly molecular engineering required to synthesize a singlematerial having the desired glass transition temperature and modulus.

In one embodiment, the binder is capable of being cured or gelledrelatively quickly so that the abrasive composite can be quicklyfabricated. Some binders gel relatively quickly, but require a longertime to fully cure. Gelling preserves the shape of the composite untilcuring commences. Fast curing or fast gelling binders can result incoated abrasive articles having abrasive composites of high consistency.Examples of binders suitable for the present invention include, but arenot limited to: thermoplastic resins, phenolic resins, aminoplastresins, urethane resins, epoxy resins, acrylate resins, acrylatedisocyanurate resins, urea formaldehyde resins, isocyanurate resins,acrylated urethane resins, acrylated epoxy resins, hot melt glue, andmixtures thereof.

Depending on the binder used, the curing or gelling can be carried outby an energy source as known by one of skill in the art. For example,the energy source may include, but is not limited to: heat, infraredirradiation, electron beam, ultraviolet radiation, or visible radiation.A radiation-curable binder is any binder that can be at least partiallycured or at least partially polymerized by radiation energy. Typically,these binders polymerize via a free radical mechanism.

If the binder is cured by ultraviolet radiation, a photoinitiator isrequired to initiate free radical polymerization. Examples ofphotoinitiators include, but are not limited to: organic peroxides, azocompounds, quinones, benzophenones, nitroso compounds, acryl halides,hydrazones, mercapto compounds, pyrylium compounds, triacrylimidazoles,bisimidazoles, chloralkyltriazines, benzil ketals, thioxanthones, andacetophenone derivatives. Other examples include, but are not limitedto: benzoin and its derivatives such as alpha-methylbenzoin;alpha-phenylbenzoin; alpha-allylbenzoin; alpha-benzylbenzoin; benzoinethers such as benzil dimethyl ketal (e.g., as commercially available asIRGACURE 651 from Ciba Specialty Chemicals, Tarrytown, N.Y.), benzoinmethyl ether, benzoin ethyl ether, benzoin n-butyl ether; acetophenoneand its derivatives such as 2-hydroxy-2-methyl-1-phenyl-1-propanone(e.g., as DAROCUR 1173 from Ciba Specialty Chemicals) and1-hydroxycyclohexyl phenyl ketone (e.g., as IRGACURE 184 from CibaSpecialty Chemicals);2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (e.g.,as IRGACURE 907 from Ciba Specialty Chemicals;2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone (e.g.,as IRGACURE 369 from Ciba Specialty Chemicals). Other examples includephosphorus-containing organic molecules, such asbis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (e.g. IRGACURE 819 fromCiba Specialty Chemicals) and ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate (e.g. TPO-L from Ciba Specialty Chemicals). Still moreuseful photoinitiators include, for example, pivaloin ethyl ether,anisoin ethyl ether, anthraquinones (e.g., anthraquinone,2-ethylanthraquinone, 1-chloroanthraquinone, 1,4-dimethylanthraquinone,1-methoxyanthraquinone, or benzanthraquinone), halomethyltriazines,benzophenone and its derivatives, iodonium salts and sulfonium salts,titanium complexes such asbis(eta5-2,4-cyclopentadien-1-yl)-bis[2,6-difluoro-3(1H-pyrrol-1-yl)phenyl]titanium(e.g., as CGI 784DC from Ciba Specialty Chemicals); andhalonitrobenzenes (e.g., 4-bromomethylnitrobenzene), mono- andbis-acylphosphines (e.g., as IRGACURE 1700, IRGACURE 1800, IRGACURE1850, and DAROCUR 4265 all from Ciba Specialty Chemicals). In oneembodiment, more than one photoinitiator is used. One or more spectralsensitizers (e.g., dyes) may be used in conjunction with thephotoinitiator(s) to, for example, increase sensitivity of thephotoinitiator to a specific source of actinic radiation.

In one embodiment, the abrasive composite includes between about 15 andabout 35%, particularly between about 22 and about 28%, and moreparticularly between about 24 and about 27% by weight soft crosslinkablebinder component. In one embodiment, the abrasive composite includesbetween about 8 and about 28%, particularly between about 10 and about15%, and more particularly between about 11 and about 14% by weight hardcrosslinkable binder component. In one embodiment, the abrasivecomposite includes between about 0.5 and about 5%, particularly betweenabout 0.6 and about 1%, and more particularly between about 0.7 andabout 0.9% by weight material capable of initiating additionpolymerization.

The binder may be radiation-curable through an addition polymerizationmechanism. To promote an association bridge between the binder and theparticulate grains, a silane coupling agent may be included in theslurry of particulate grains and binder precursor. In one embodiment,the silane coupling agent may be present in an amount of between about 0and about 1%, particularly between about 0.05 and about 0.4% by weight,and more particularly between about 0.1 and about 0.3% by weight.However, one of skill in the art will know that other amounts may alsobe used, depending, for example, on the size of the minerals. Suitablesilane coupling agents include, for example, methacryloxypropylsilane,vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane,3,4-epoxycyclohexylmethyltrimethoxysilane,gammaglycidoxypropyl-trimethoxysilane, andgamma-mercaptopropyltrimethoxysilane (e.g., as available under therespective trade designations A-174, A-151, A-172, A-186, A-187, andA-189 from Witco Corp. of Greenwich, Conn.), allyltriethoxysilane,diallyldichlorosilane, divinyldiethoxysilane, and meta,para-styrylethyl-trimethoxysilane (e.g., as commercially available underthe respective trade designations A0564, D4050, D6205, and S1588 fromUnited Chemical Industries, Bristol, Pa.), dimethyldiethoxysilane,dihydroxydiphenylsilane, triethoxysilane, trimethoxysilane,triethoxysilanol, 3-(2-aminoethylamino) propyltrimethoxysilane,methyltrimethoxysilane, vinyltriacetoxysilane, methyltriethoxysilane,tetraethyl orthosilicate, tetramethyl orthosilicate,ethyltriethoxysilane, amyltriethoxysilane, ethyltrichlorosilane,amyltrichlorosilane, phenyltrichlorosilane, phenyltriethoxysilane,methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane,dimethyldiethoxysilane, and mixtures thereof.

Other materials can be added to the abrasive composite for specialpurposes including, but not limited to: monofunctional acrylic monomers,thermal free radical initiators, accelerators, polymer waxes or beads,leveling agents, wetting agents, matting agents, colorants, dyes,pigments, slip agents, adhesion promoters, fillers, rheology modifiers,thixotropic agents, plasticizers, UV absorbers, UV stabilizing agents,dispersants, antioxidants, antistatic agents, lubricants, opacifyingagents, anti-foam agents, antimicrobial agents, fungicides, andcombinations thereof. In one embodiment, the additives are organic. Inone embodiment, the abrasive composite includes up to about 1%,particularly between about 0.1 and about 0.8%, and more particularlybetween about 0.2 and about 0.6% by weight dispersant. In oneembodiment, the abrasive composite includes up to about 1%, particularlybetween about 0.05 and about 0.4%, and more particularly between about0.1 and about 0.3% by weight coupling agent. In one embodiment, theabrasive composite includes up to about 1%, particularly up to about0.3%, and more particularly up to about 0.2% by weight colorant. In oneparticular embodiment, the abrasive composite includes between about 15and about 35% by weight, particularly between about 22 and about 28% byweight, and more particularly about 26.8% by weight soft crosslinkablebinder component; between about 8 and about 28%, particularly betweenabout 22 and about 15%, and more particularly about 12.6% by weight hardcrosslinkable binder component; between about 0.5 and about 5%,particularly between about 0.6 and about 1%, and more particularly about0.8% by weight photoinitiator; between about 25 and about 55%,particularly between about 35 and about 45%; and more particularly about42.1% by weight of a first particulate grain; and between about 1 andabout 25%, particularly between about 12 and about 20%, and moreparticularly about 16.9% by weight of a second particulate grain.

While the abrasive composite includes a binder phase and a mineralphase, the mineral phase does not contribute to the scouring ability ofthe abrasive composite and functions more as a filler. Rather, thescouring performance arises from the properties of the binder phase andthe mineral phase as a whole.

In one embodiment, the abrasive composites are used to form a structuredabrasive article including a plurality of precisely shaped abrasivecomposites attached to a substrate. “Precisely shaped abrasivecomposite”, as used herein, refers to abrasive composites having a shapethat has been formed by curing one or more binder components of aflowable mixture also containing soft mineral grains while the mixtureis both being borne on a backing and filling a cavity on the surface ofa production tool. Such precisely shaped abrasive composites haveprecisely the same shape as that of the cavity. In one embodiment, theabrasive composites can be pyramidal, the dimensions of which aresubstantially precise.

When forming a structured abrasive article, the plurality of preciselyshaped abrasive composites is attached to at least one major surface ofa substrate. The precisely shaped abrasive composites providethree-dimensional shapes that project outward from the surface of thesubstrate. The abrasive composites can be disposed on the substrate ineither a pattern (i.e., non-random array) or a random array. In oneembodiment, the abrasive composites are disposed on the substrate in anon-random array that exhibits some degree of repetitiveness.

Materials suitable for the substrate of the present invention include,but are not limited to: polymeric film, paper, cloth, metallic film,vulcanized fiber, nonwoven substrates, combinations thereof, andchemically treated versions thereof. In one embodiment, the substrate isa polymeric film, such as polyester or polyurethane film. In oneembodiment, the substrate is transparent to ultraviolet radiation. Inone embodiment, the substrate is coated with an adhesion-promotinglayer, such as poly(ethylene-co-acrylic acid) or a UV-curable “tie coat”layer, or undergo adhesion-promoting surface modification, such ascorona or flame treatment or electron beam irradiation. The substratecan be laminated to another substrate after the coated abrasive articleis formed. For example, the substrate can be laminated to a flexible orstiff polyurethane foam material, providing a means for effectivemanipulation of the abrasive by the user.

Production tools may be used to form abrasive articles having preciselyshaped abrasive coatings or to produce precisely shaped abrasivecomposites. A production tool has a surface defining a main plane, whichcontains a plurality of cavities distending as indentations from themain plane. These cavities define the inverse shape of the abrasivecomposite and are responsible for generating the shape, size, andplacement of the abrasive composites. The cavities can be provided inessentially any geometric shape that is the inverse of a geometric shapewhich is suitable for an abrasive composite or abrasive compositeparticle. For example, the abrasive composites may be cubic,cylindrical, prismatic, hemispheric, rectangular, pyramidal, truncatedpyramidal, conical, truncated conical, and post-like with a flat topsurface. The dimensions of the cavities are selected to achieve thedesired areal density of abrasive composites. In one embodiment, thecavities can be present in a dot like pattern where adjacent cavitiesbutt up against one another. In one embodiment, the shape of thecavities is selected such that the surface area of the abrasivecomposite decreases away from the backing.

The production tool can take the form of a belt, sheet, continuous sheetor web, coating roll such as a rotogravure roll, sleeve mounted on acoating roll, or die. In one embodiment, the production tool isreplicated from a master tool. The master tool can be fabricated by anyconventional technique known to those of skill in the art, including butnot limited to: photolithography, knurling, engraving, hobbing,electroforming, and diamond turning. U.S. Pat. No. 5,851,247 (Stoetzelet al.) describes a production tool made of thermoplastic material thatcan be replicated from a master tool, and is hereby incorporated byreference. When a production tool is replicated from a master tool, themaster tool is provided with the inverse of the pattern which is desiredfor the production tool. In one embodiment, the master tool is made of anickel-plated metal, such as nickel-plated aluminum, nickel-platedcopper, or nickel-plated bronze. A production tool can be replicatedfrom a master tool by pressing a sheet of thermoplastic material againstthe master tool while heating the master tool and/or the thermoplasticsheet such that the thermoplastic material is embossed with the mastertool pattern. Alternatively, the thermoplastic material can be extrudedor cast directly onto the master tool. The thermoplastic material isthen cooled to a solid state and is separated from the master tool toproduce a production tool. The production tool may optionally contain arelease coating to permit easier release of the abrasive article.Examples of suitable release coatings include, but are not limited to:silicones and fluorochemicals. Preferred methods for the production ofproduction tools are disclosed in U.S. Pat. No. 5,435,816 (Spurgeon etal.), U.S. Pat. No. 5,658,184 (Hoopman et al.), and in U.S. Ser. No.08/923,862, “Method and Apparatus for Knurling a Workpiece, Method ofMolding an Article with Such Workpiece, and Such Molded Article”(Hoopman), filed Sep. 3, 1997), the disclosures of which areincorporated herein by reference.

The rheology of the abrasive composite prior to curing is critical toits ability to be coated in high fidelity to a production tool'scavities if used to form an abrasive article. In one embodiment, thestructured abrasive article can be made by first introducing a flowableand curable slurry containing a mixture of a binder precursor and aplurality of minerals into cavities contained on an outer surface of aproduction tool to fill such cavities. A substrate is then introduced tothe outer surface of the production tool over the filled cavities suchthat the slurry wets one major surface of the substrate to form anintermediate article. The binder is then cured before the intermediatearticle departs from the outer surface of the production tool to form acoated, structured abrasive article. The coated, structured abrasivearticle is then removed from the surface of the production tool.

In another embodiment, the structured abrasive article can be made byfirst introducing a flowable and curable slurry containing a mixture ofa binder precursor and plurality of minerals onto a front side of asubstrate such that the slurry wets the front side of the substrate toform an intermediate article. The slurry is then introduced to thebearing side of the intermediate article to an outer surface of aproduction tool having a plurality of cavities in its outer surface suchthat the cavities are filled. The binder precursor is then cured beforethe intermediate article departs from the outer surface of theproduction tool to form a coated, structured abrasive article. Thecoated, structured abrasive article is then removed from the surface ofthe production tool.

In both of the methods described, in one embodiment, the steps arecarried out in a continuous manner, providing an efficient method ofmaking the structured abrasive article of the present invention.

In practice, the structured abrasive article is used as a cleaningarticle. The cleaning article can take a variety of forms, including,but not limited to: a wipe construction, a hand pad, or a handled good.In the wipe construction, shown in FIG. 1 , the cleaning articleincludes the abrasive composite and the substrate. When in the form of awipe, the substrate may include a substantially thin and flexiblematerial such as, but not limited to: a nonwoven, a woven, a foam, etc.

When the cleaning article is in the form of a hand pad, as shown in FIG.2 , the structured abrasive article may be attached to a substrate, suchas a conformable material including to allow a user to have a bettergrip on the cleaning article. Any material can be used that allows thestructured abrasive article to conform around surfaces to be cleaned. Inone embodiment, the substrate may include, but is not limited to, foamor soft polymer network including a rubber/elastomer or gel material.This allows the user to better manipulate the structured abrasivearticle for more effective cleaning. In such a construction, thecleaning article would include the abrasive composite positionedadjacent a first side of the substrate and the second side of thesubstrate positioned adjacent the foam layer. The foam layer may beattached to the substrate by any means known to those of skill in theart, including, but not limited to, mechanical or adhesive means.

In use, the structured abrasive article may be attached to a grip orhandle, as seen in FIG. 3 . The structured abrasive article may bepermanently or releasably attached to the grip or handle by anattachment mechanism. The grip or handle may be attached to thestructured abrasive article by any means known to those of skill in theart. Exemplary attachment methods include mechanical means or adhesivemeans. One exemplary mechanical attachment mechanism includes usingplastic snaps. For example, the structured abrasive article can beattached to the grip or handle by engagement of an insertable portion ofthe grip or handle into a shoe or cup attached to the structuredabrasive article. The shoe or cup may be attached to the structuredabrasive article through adhesive or mechanical means. To effect thisengagement, the user inserts the insertable portion of the grip orhandle into the cup or shoe of the structured abrasive article andpushes or exerts force to guide the grip or handle thinly into/onto thecup or shoe. The user's force causes the at least one snap in theinsertable portion of the grip or handle to flex or push inwardly. Thispermits the insertable portion to slide into the cup or shoe. When thesnaps align with corresponding slots on the cup or shoe, the snaps enterinto the slots and return generally to their original non-flexed(relaxed) position. In this way, the snaps engage with the slots of thecup or shoe attached to the structured abrasive article. In this engagedposition, the snaps attach the structured abrasive article to the gripor handle and holds the structured abrasive article in place.

In one embodiment when the structured abrasive article is attached to agrip or handle, an additional layer is positioned between the structuredabrasive article and the handle or grip. For example, a layer of foam,soft polymer, or other conformable material may be positioned betweenthe structured abrasive article and the grip or handle. In thisembodiment, the foam layer may be attached to the structured abrasivearticle by any means known in the art, including, but not limited to,mechanical or adhesive means. The grip or handle is then attached(permanently or releasably) to the foam layer. The overall structure ofthe cleaning article includes the abrasive composite positioned adjacentto a first side of the substrate, a second side of the substratepositioned adjacent a first side of the foam layer, and a second side ofthe foam layer positioned adjacent and attached to the handle or grip.

In some embodiments, the attachment mechanism includes an actuationbutton or switch on the grip or handle. When the actuation button ispushed, the structured abrasive article is ejected or released fromattachment to the grip or handle. In this embodiment, the user canactivate the activation mechanism by activating button or switch and canthen insert the insertable portion of the grip or handle into the shoeor cup of the structured abrasive article. When the button or switch isactivated, the snaps on the grip or handle flex or push inwardly. Thisenables the structured abrasive article to easily slide onto the grip orhandle. Once the structured abrasive article is on the grip or handle,the user releases or slides the button or switch into its originalposition. This causes the snaps to engage with the slots on the shoe orcup and hold the structured abrasive article firmly in place on the gripor handle.

To detach the structured abrasive article from the grip or handle, theuser activates the button or switch. This generates enough force to pushor flex the snaps inward and to release the snaps from the slots. Thesnaps are capable of flexural motion such that they can flex inward,providing additional “give” to release the structured abrasive articlefrom the grip or handle. Once the snaps are pushed inward, thestructured abrasive article slides off of the insertable portion. Inthis way, the structured abrasive article is easily detached from thegrip or handle without requiring the user to touch the structuredabrasive article. Various modifications and changes may be made to thespecific embodiment described without departing from the spirit andscope of the present disclosure.

The grip or handle may be made of any suitable material. In someembodiments, the grip or handle may be molded. In some embodiments, thegrip or handle is made of a polymeric material such as acrylonitrilebutadiene (ABS), polyethylene, polypropylene, polycarbonate, or highimpact polystyrene. In some embodiments, the handle may feature“overmolded” components designed to enhance the user's grip on the tool.Such components are generally made from urethane-based elastomers orhydrocarbon-based block copolymer elastomers likestyrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), orstyrene-ethylene-butylene-styrene (SEBS) materials.

EXAMPLES

The present invention is more particularly described in the followingexamples that are intended as illustrations only, since numerousmodifications and variations within the scope of the present inventionwill be apparent to those skilled in the art. Unless otherwise noted,all parts, percentages, and ratios reported in the following examplesare on a weight basis.

Materials Abbreviation Description and Source Purpose AUDA Aliphaticurethane diacrylate, obtained under Difunctional the trade designationEBECRYL 8402 from acrylate monomer Allnex USA, Inc, Alpharetta, GA(soft, rubbery) TMPTA Trimethylolpropane triacrylate, obtained underTrifunctional the trade designation SR351H from Sartomer acrylatemonomer Americas, Inc., Exton, PA (hard, stiff) PI Ethyl(2,4,6-trimethylbenzoyl) phenyl Photoiniator phosphinate photoinitiator,obtained under the trade designation TPO-L from IGM Resins BV,Netherlands DISP Phosphonated copolymer dispersant, obtained Dispersant,under the trade designation SOLPLUS D520 viscosity modifier fromLubrizol Corporation, Wickliffe, OH CAGamma-Methacryloxypropyltrimethoxy silane Coupling agent, couplingagent, obtained under the trade viscosity modifier designation SILQUESTA-174NT from Momentive Performance Materials, Inc. Waterford, NY TACalcium sulfate dihydrate (gypsum), obtained Filler, under the tradedesignation Terra Alba No.1 viscosity modifier from USG Corporation,Chicago, IL PCC Precipitated calcium carbonate, obtained under Filler,the trade designation ALBAFIL T10 from viscosity modifier SpecialtyMinerals, Inc., Bethlehem, PA

Test Methods Article Cleaning Efficacy Test (Food Soil Cleaning)

The article cleaning efficacy test was performed in a generally similarmanner as that described in U.S. Pat. No. 5,626,512 (Palaikis et al). A5 mm thick, 4 inch diameter stainless steel disc was coated with a foodsoil mixture made up of 120 grams milk, 60 grams cheddar cheese, 120grams hamburger, 120 grams tomato juice, 120 grams cherry juice, 20grams flour, and 100 granulated sugar, and one egg. The coated panel wasbaked in an oven at 230° C. for one hour. The above coating and curingprocess was repeated three times to achieve uniform coat on the panel.Acceptable food soil coating weight should be at least equal to 0.9grams. Test samples measuring about 1 in², comprising precisely shapedabrasive composites affixed to polymeric film, were cut from a largersample of each abrasive article. The sample contacted the food soil discby virtue of force transmitted through a 1 inch thick piece of foam by asingle finger-like projection (having approximately 0.08 inch² contactarea with the sample) having 5 pounds of weight on top of it. Theassembly comprising the weight, finger-like projection, foam, andabrasive sample were pushed/pulled by hand, using a track as guide. overthe coated panel until the abraded region of the coated panel was clean(no coated material visually remained on the panel). The travel lengthwas 2 inches. The number of cycles (back and forth equals one cycle witha rate of approximately 45 cycles per minute) required to result in aclean panel was recorded.

Scratch-Testing Procedure

Test samples, comprising precisely shaped abrasive composites affixed topolymeric film, measuring about 3 cm² were cut from a larger sample ofeach abrasive article. The test samples were pushed with the side of thetester's thumb into the test surface, exerting about five pounds offorce, and pushed and pulled back and forth over the surface for fiveseconds. Then, the surfaces were visually examined for changes insurface finish. The poly(tetrafluoroethylene) (PTFE) surface tested wasthat of a nonstick frying pan, and the chrome surface was that of a drippan for an electric coil cooking range.

Durability Test (abrasion weight loss) This test was used to determinethe durability of the abrasive articles and involved rubbing eachabrasive article sample back and forth over an abrading material withthe percent weight loss noted after the test. A lower percent weightloss indicated a more durable product. Wear testing was performed in agenerally similar manner as described in U.S. Pat. No. 5,681,361(Sanders, Jr.) The test sample size was 2.5 inches×9.0 inches (63.5mm×228.6 mm). The downward load applied to the test sample was 2.25 kg.The percent weight loss was determined after 100 linear passes back andforth (travel length was about 14 inches) over a conditioned (broken-in)M125 Diamond Cloth belt (3M Company, St. Paul, MN) in the presence ofwarm water.

Examples EX1-EX7

Preparation of Binder Precursor with Dispersed Soft Mineral Grains

Liquid components AUDA, TMPTA, PI, DISP, and CA were added to aSPEEDMIXER cup and mixed at 2400 rpm for 60 seconds in a DAC 400.2 VAC-PSPEEDMIXER (FlackTek, Inc, Landrum, SC). Then TA and PCC were added tothe cup, completing a total batch size of 200 grams, and the mixture wasmixed for 30 seconds at 1200 rpm. The mixture was then placed in an ovenat 150° F. (66° C.) for 30 minutes, after which it was mixed for 3minutes at 2400 rpm to provide a liquid slurry of a binder precursor anda plurality of soft mineral grains.

TABLE 1 Formulas for Examples EX1-EX7 AUDA TMPTA PI DISP CA TA PCC (wt%) (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) EX1 13.20 26.39 0.81 0.400.20 39.33 19.67 EX2 23.76 15.84 0.81 0.40 0.20 39.33 19.67 EX3 27.4112.18 0.81 0.40 0.20 39.33 19.67 EX4 29.69 9.90 0.81 0.40 0.20 39.3319.67 EX5 27.41 12.18 0.81 0.40 0.20 57.82 1.18 EX6 27.41 12.18 0.810.40 0.20 53.10 5.90 EX7 27.41 12.18 0.81 0.40 0.20 49.17 9.83

Preparation of Coated Abrasive Articles

Coated abrasive articles were prepared using a method similar to thosedescribed in U.S. Pat. No. 5,152,917 (Pieper et al) (for example, seeExamples 1-5) and U.S. Pat. No. 7,267,700 (Collins et al) (for example,see Column 11, lines 9-34). A production tool was provided having anouter surface that had a plurality of cavities that corresponded to theinverse shape of the desired abrasive composite shape. The cavities eachhad a shape resembling that of a pyramid with a base length of 400-700microns and a height of 450 microns. For each of the Example EX1-X7formulas, a liquid slurry of the binder precursor and plurality of softmineral grains was coated into the cavities of the production tool. Abacking was then introduced to the outer surface of the production toolover the filled cavities such that the slurry wetted one major surfaceof the backing to form an intermediate article. The backing was apolyester film (3 mil thick) with a corona-treatedpoly(ethylene-co-acrylic acid) primer layer (0.81 mil thick) to primethe film. Next, the production tool containing the slurry and the softmineral grains was exposed to UV radiation to cure the binder precursor.Then the abrasive article was removed from the production tool.

The abrasive articles of Examples EX1-EX7 were then tested for cleaningefficacy (food soil cleaning), scratching properties, and durability(abrasion weight loss) using the above Test Methods. For comparison,Comparative Example CE1 was also tested. Comparative Example CE1 was astandard density foam of a melamine-formaldehyde thermoset resin,obtained from BASF in 1 inch thickness. Results are provided in Table 2.

TABLE 2 Cleaning ability, scratching properties, and durability testresults Abrasion Food soil Scratches weight cleaning Scratches polishedloss UADA:TMPTA TA:PCC cycles Teflon? chrome? (wt %) EX1 0.50 2 8 Yes No16.0 EX2 1.50 2 12 No No 12.8 EX3 2.25 2 23 No No 13.4 EX4 3.00 2 34 NoNo 14.4 EX5 2.25 49 79 No No 8.1 EX6 2.25 9 58 No No 6.5 EX7 2.25 5 39No No 5.6 CE1 NA NA 280 No No 55 Note that the non-scratch properties ofthe abrasive articles can be tuned by adjusting the UADA:TMPTA and/orTA:PCC ratios. Increases in each ratio lead to a softer, more compliantabrasive article that will generally scratch less, yet also require moreeffort when used to clean a surface.

Various modifications and alterations to this disclosure will becomeapparent to those skilled in the art without departing from the scopeand spirit of this disclosure. It should be understood that thisdisclosure is not intended to be unduly limited by the illustrativeembodiments and examples set forth herein and that such examples andembodiments are presented by way of example only with the scope of thedisclosure intended to be limited only by the claims set forth herein asfollows. All references cited in this disclosure are herein incorporatedby reference in their entirety.

What is claimed is:
 1. An abrasive composite comprising: a firstcrosslinkable binder component, wherein when polymerized, has a glasstransition temperature (T_(g)) below room temperature and a modulus ofless than about 150 MPa; a second crosslinkable binder component havinga T_(g) above room temperature; a material capable of initiatingaddition polymerization; and particulate grains having a Mohs hardnessvalue of less than or equal to about
 3. 2. The abrasive composite ofclaim 1, wherein the first crosslinkable binder component comprisesurethane diacrylate or triacrylate.
 3. The abrasive composite of claim1, wherein when polymerized, the first crosslinkable binder componenthas an elongation percent at break of greater than about 25%.
 4. Theabrasive composite of claim 1, wherein the second crosslinkable bindercomponent comprises a difunctional or trifunctional acrylate.
 5. Theabrasive composite of claim 1, wherein the material capable ofinitiating addition polymerization comprises a UV photoinitiator.
 6. Theabrasive composite of claim 1, wherein the particulate grains comprisean inorganic mineral having a d₉₀ of less than about 50 micron.
 7. Theabrasive composite of claim 1, wherein the abrasive composite includesbetween about 15 and about 35% by weight of the first crosslinkablebinder component.
 8. The abrasive composite of claim 1, wherein theabrasive composite includes between about 8 and about 28% by weight ofthe second crosslinkable binder component.
 9. The abrasive composite ofclaim 1, wherein the abrasive composite includes between about 0.5 andabout 2% by weight of the material capable of initiating additionpolymerization.
 10. The abrasive composite of claim 1, wherein theabrasive composite includes between about 26 and about 80% by weight ofthe particulate grains.
 11. The abrasive composite of claim 1, whereinthe particulate grains comprise gypsum.
 12. The abrasive composite ofclaim 1, comprising at least a first particulate grain and a secondparticulate grain.
 13. A structured abrasive article comprising: asubstrate; and an abrasive composite adhered to the substrate, whereinthe abrasive composite comprises: a first crosslinkable bindercomponent, wherein when polymerized, has a glass transition temperature(T_(g)) below room temperature and a modulus of less than about 150 MPa;a second crosslinkable binder component having a T_(g) above roomtemperature; a material capable of initiating addition polymerization;and particulate grains having a Mohs hardness value of less than orequal to about
 3. 14. The structured abrasive article claim 13, whereinthe structured abrasive article is attached to a handle.
 15. Thestructured abrasive article of claim 13, wherein the structured abrasivearticle is releasably attached to a handle.
 16. The structured abrasivearticle claim 14, wherein the structured abrasive article is attached tothe handle by mechanical means.
 17. The structured abrasive articleclaim 14, wherein the structured abrasive article is attached to thehandle by an adhesive.
 18. The structured abrasive article of claim 13,further comprising a conformable layer positioned adjacent thesubstrate.
 19. The structured abrasive article of claim 18, furthercomprising a handle, wherein the conformable layer is positioned betweenthe structured abrasive article and the handle.